Runway Characters
Zero-shot avatar from image with tool calling and RAG
TTFR Latency
~400ms
real-time
Cost / minute
$0.210/min
real-time
Visual Quality
8/10
estimated score
Protocols
WebRTC, REST
Avatar Customisation
RAG / Knowledge Base
Upload .txt files as knowledge base. Avatar queries them in real-time. Tool Calling enables external action triggers during conversation.
Behavior & Personality
Personality via system prompt (overridable per session). Voice style presets (professional, authoritative, etc.).
Body Language & Gestures
Fixed by reference image. Model generates natural body language but no granular API control.
Facial Expressions
GWM-1 generates natural micro-expressions and facial movements. Not manually scriptable.
Voice & Voice Cloning
Voice presets (Clara, Vincent, etc.) with style variations. No custom voice cloning via Characters API at launch.
Persona Fine-Tuning
System prompt overridable per session call. Tool Calling for external integrations. Starting script customisable.
Avatar Training
Best Practices
- 01.Front-facing, well-lit, face centered
- 02.No obstructions (sunglasses, hair over face)
- 03.Works with human, stylized, or mascot images
- 04.No audio samples needed for built-in voices
API Analysis
Protocols
SDKs
Concurrent Sessions
Plan-dependent
Rate Limits
Session max: 5 minutes. Pre-provisioning required (NOT_READY → READY state).
Key Features
- Avatar ID management via REST
- Session lifecycle: NOT_READY → READY → RUNNING → COMPLETED/FAILED
- Dynamic personality override per session
- Tool Calling for external action triggers
- Webhooks: READY, RUNNING, COMPLETED, FAILED
API Constraints
- 5-minute maximum session duration
- Pre-provisioning required before WebRTC connection
- No custom voice cloning via Characters API
- US hosting only
Pricing Model
| Plan | Price | Included minutes | Overage |
|---|---|---|---|
| Pay-as-you-go | Credits only | ~$0.21/min | N/A |
| Standard | ~$12/mo | Included credits | $0.21/min |
| Pro | ~$28/mo | More credits | $0.21/min |
| Enterprise | Custom | Custom | Custom |
Hidden costs / watch out
- 2 credits init per session ($0.02 fixed)
- Runway subscription may be required for advanced features
Sovereignty & Hosting
Sovereignty Score
Hosting
AWS US
GDPR
YesOn-premise
NoSovereignty detail
AWS US. SOC2 Type II. GDPR/CCPA compliant. No EU hosting, no on-premise.
Constraints & Limits
- 5-minute maximum session duration
- No custom voice cloning in Characters API
- No manual body gesture control
- US hosting only
- Pre-provisioning adds latency before session start
DigiDouble Relevance
Score
7/10
Tool Calling is a unique differentiator for interactive educational scenarios. Zero-shot from image is excellent for rapid prototyping. 5-min session limit is a significant constraint for DigiDouble's longer interaction scenarios.